In the art of coupling pipes, much attention has necessarily been given to the problem of obtaining a fluid-tight seal so that there will be no leakage at the connection. When the pipes are to carry, e.g., water at a relatively low pressure, prior-art workers have provided successful connectors which employ O-rings or like sealing rings and which will tolerate a relatively small angular misalignment between the two pipes, or between one length of pipe and a device such as a tank. But, when the connection is intended to conduct, e.g., hydraulic pressure fluid at relatively high pressures of, e.g., up to 2000 p.s.i., such relatively simple couplings have not heretofore achieved real success and it has become common practice to use expensive ground joint couplings or unions which, despite their high cost, have frequently proved undependable when the pipes being coupled are angularly misaligned and the system is subjected to prolonged service. Thus, for many applications where fluid under relatively high pressure must be handled, and particularly for the pressure fluid systems of presses used to press tobacco, textile materials and the like, there has been a continuing need for an improved approach to coupling pipes which will be more dependable and less expensive than when the pipes are coupled with a ground joint union.